ABSTRACT
Surface (crest) gates are used for controlling the inlet parts of water conveyance structures that serve for intake of water at the surface, without water pressure. In the cases of hydraulic schemes with dams, these gates are mainly used with surface spillways, aiming at controlled discharge of floodwaters. A number of different surface (crest) gates may be differentiated, of which the basic ones are presented in Figure 24.1:
(a) Plain gate. During closing or opening, the gate (1) moves along vertical gate slots (2), provided in the sidewalls or piers; it is also sometimes called a sluice gate.
